AT 505 950 B1 describes a current generating unit for extending the range of an electric vehicle, comprising a rotary-piston engine and a generator which is arranged coaxially to the output shaft of the internal combustion engine. The internal combustion engine and the generator are arranged as a unit and comprise a common cooling system. The cooling water reaches water chambers of the generator and the internal combustion engine from a coolant pump and will be supplied thereafter to the air/water heat exchangers. The cooling channels of the generator and the internal combustion engine are directly flow-connected to each other without any separate lines.
Furthermore, a unit consisting of a current generator and an internal combustion engine is known from DE 3 601 193 A1, with the internal combustion engine and the generator having a common cooling water circuit, with the line originating from the generator and discharging the generator heat being connected to the cooling water inlet of the engine.
DE 4 020 416 A1 describes a generator with armature shaft cooling, with the generator and a drive motor formed by an internal combustion engine having a common cooling system.
WO 02/052132 A1 describes a cooling system for a motor vehicle with at least one coolant pump, with a starting generator and power electronics being included in the cooling circuit. The cooling of the power electronics occurs parallel to the cooling of the starting generator.
The specification DE 40 20 176 A1 describes a power unit for the power supply of a motor vehicle whose cooling circuit is connected to the cooling circuit of the motor vehicle.
In the current generating unit, the individual components have different heat inputs and different optimal operating temperatures.